1. Field of the Invention
The present invention relates generally to endobronchial tubes for insertion through the mouth or nasal passages of a patient to facilitate artificial ventilation of the respiratory system. More particularly, this invention relates to endobronchial tubes with a double lumen and balloon cuffs for selective ventilation of one or both lungs of a patient.
2. Background Art
It is a common practice to provide human medical patients with artificial ventilation during surgery or in emergency situations. For example, accident victims will frequently require CPR or intubation by a paramedic in an emergency vehicle or by an anesthesiologist in an operating room. In such situations, intubation is accomplished by insertion of a breathing tube through the patient""s mouth or nasal passages into the airway passage. Such devices have generally comprised a relatively pliable tube that is connectable to a respirator or other air supply mechanism for introduction of air into the lungs. An improvement to breathing tubes includes an inflatable-deflatable bag-like structure or balloon xe2x80x9ccuffxe2x80x9d around the exterior of the tube. The balloon cuff is conventionally located in a position along the breathing tube to engage the inner wall of the pharynx, larynx, or trachea, depending upon the specific breathing tube design. When the tube is in place, the cuff is inflated and forms an air tight seal between the tube and the surrounding body tissue to prevent the escape of air pumped from the respirator into the lungs.
Both single lumen and double lumen breathing tubes are known. Typically, a single lumen breathing tube is an elongated tube that extends into the trachea of a patient and includes one inflatable balloon cuff near its distal end. Commonly, the double lumen breathing tube is referred to as an endobronchial tube and, in addition to one lumen which extends to the trachea, has a second longer lumen which extends into the bronchus of a patient upon intubation. Typically, the double lumen breathing tube or endobronchial tube includes two inflatable balloon cuffs. The double lumen breathing tubes, such as the well known xe2x80x9cCarlensxe2x80x9d and xe2x80x9cRobertshawxe2x80x9d tubes, allow for independent control of each lung through the separate lumens. One bronchus may be blocked by occluding one of the lumens at a position external to the patient, in order to isolate a particular lung.
The balloon cuffs are thin walled, high volume, and low pressure chambers or vessels that are designed to avoid compromising the blood flow in the tracheal or bronchial wall when inflated. Balloon cuffs are made of a soft expandable plastic and can be inflated by detachable syringes that are connected to smaller lumens or channels at the proximal end of the breathing tube. The seals formed by the inflated cuffs preclude the air that has been forced into the patient""s lungs from escaping through the trachea or bronchus. Additionally, the seals formed by the inflated cuffs provide a barrier to the flow of blood and secretions.
The double lumen breathing tubes offer an anesthesiologist the ability to ventilate selectively either the right or left lung or both lungs as required. One potential problem with currently used double lumen breathing tubes, however, is the obstruction of the right upper lobe bronchus. Correct placement of the currently available double lumen tubes requires confirmation with fiberoptic bronchoscopy. Moreover, currently available double lumen tubes can be easily displaced after correct placement, especially when the patient is repositioned on the operating table.
The present invention provides an improvement over the prior art because its proper positioning is assured by its unique design; thus, the need for fiberoptic bronchoscopy is minimized. Moreover, the present invention is more securely placed with less risk for malposition after placement, compared to currently available double lumen tubes.
The present invention comprises a double lumen breathing tube comprising two tubes disposed adjacent to each other. Each tube has a lumen, a proximal end, a distal end and a length extending between the proximal and distal ends. The two tubes are fixedly attached to each other along a portion of their respective lengths. A first branch section is a section of length of the first tube extending from the distal end of the first tube to a proximal location at which the first and second tubes are fixedly attached to each other. A second branch section is a section of length of the second tube extending from the distal end of the second tube to a proximal location at which the first and second tubes are fixedly attached to each other. The first branch section is preferably longer than the second branch section. The first branch section and the second branch section are also preferably predisposed to be spaced-apart from each other. Each proximal end can be individually attached to a ventilating machine, or respirator, so that either one or both tubes can be connected to a ventilation source at any given time.
As one skilled in the art will appreciate, the predisposition of the first branch section and the second branch section to be spaced-apart from each other hinders the insertion of the double lumen tube into the patient""s airway. Accordingly, the present invention also provides a means for temporarily positioning the first branch section and the second branch section in contact with each other along at least a portion of their respective lengths. In one embodiment, the temporarily positioning means is a stylet having a central body portion connecting two spaced-apart arms that are disposed substantially parallel to each other so that the stylet is substantially U-shaped in plan view. When each arm of the stylet is positioned within a respective lumen of the double lumen tube, at least a portion of the first and second branch sections are in contact.
In another embodiment of the present invention, the temporarily positioning means comprises a sleeve. The sleeve has an interior surface of a size to complementarily receive the first and second tubes therein. When the sleeve is moved toward the distal ends of the first and second tubes so that the distal end of at least the second tube is disposed within the sleeve, at least a portion of the first and second branch sections contact each other. When the clinician moves the sleeve proximally after insertion into the patient""s airway so that the distal end of the sleeve is proximal or adjacent to the point where the two tubes are fixedly attached, the first branch section and the second branch section move apart to their predisposed spaced-apart position.
The present invention further provides another temporarily positioning means comprising a primary spring and one or more wires interconnecting the primary spring and the distal ends of the two tubes. The wires extend along and are disposed adjacent to the first branch section and the second branch section respectively. The bottom ends of the wires are secured to the distal end of the tubes, and the wire also extends along the joined portion of the length of the first and second tubes that are fixedly attached to each other. The primary spring is movable between an extended position and a compressed position. When the primary spring is in the extended position, a portion of the first and second branch sections are in contact with each other. Alternatively, when the primary spring is compressed, the first branch section and the second branch section are spread apart from each other to their predisposed spaced-apart position.
Regardless of the temporarily positioning means used, once the double lumen breathing tube has passed through the vocal cords, the temporarily positioning means is discontinued or released, allowing the first branch section and the second branch section to move to their predisposed spaced-apart positions. Therefore, the first branch section is aligned to be positioned in the left mainstem bronchus and the second branch section is aligned to be positioned in the right mainstem bronchus.
Also, the present invention allows the clinician to place the double lumen breathing tube so that the first branch section is positioned in the left mainstem bronchus, and the second branch section is positioned in the right mainstem bronchus without obstructing the opening into either mainstem bronchus.